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1.
Environ Sci Pollut Res Int ; 30(22): 61904-61912, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36934180

RESUMO

Increasing demand for shopping and packaging carrier bags has given rise to various issues relating to its disposal as well as to the overall environmental footprint and sustainability of the packaging materials. This study assesses the carbon footprint and life cycle environmental impacts of the production, usage, and disposal of low density polyethylene (LDPE) and two natural fibre carrier bags (jute and kenaf). Life cycle assessment study was conducted of all inputs and outputs, aggregated in the form of resources used and environmental emissions, extending from the production of raw materials to the final disposal of the product. The carbon footprint and GHG emissions of jute and kenaf carrier bags were estimated using the CO2, N2O, and CH4 emissions coefficients of inputs. Research literature from life cycle impact assessment (LCIA) results was used to determine the effects of LDPE polyethylene packaging material. It was observed that the global warming potential (GWP) for the production of 1 kg of LDPE (100 micron) carrier bag (39.4 kg CO2eq) is more than 490 times higher than jute and kenaf carrier bags. In general, LDPE materials have the greatest impact on the carbon footprint and resource depletion. The LDPE material also has the highest impacts on indicators of terrestrial ecotoxicity, photochemical oxidation, acidification, and eutrophication as compared to jute and kenaf fibres. Since jute and kenaf are natural fibres, they sequester a substantial quantity of carbon during their agricultural stages. As a result, greenhouse gas (GHG) emission emissions of jute and kenaf were found to be negative. Popularising the use of jute and kenaf products as alternatives to plastic in industrialised countries would benefit the reduction of plastic waste and its negative environmental effects. Additional production of jute and kenaf fibre, which are already available in major bast fibre producing countries like India and Bangladesh, could meet the demand for fibre-based carrier bags.


Assuntos
Gases de Efeito Estufa , Hibiscus , Polietileno , Pegada de Carbono , Plásticos
2.
Bioresour Technol ; 368: 128318, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36375701

RESUMO

Reduction of inherent structural recalcitrance and improved saccharification efficiency are two important facets to enhance fermentable sugar yield for bioethanol production from lignocellulosic biomass. This study optimized alkaline pretreatment and saccharification conditions employing response surface methodology to improve saccharification yield of jute (Corchorus olitorius cv. JROB-2) biomass. The biomass is composed of cellulose (66.6 %), lignin (19.4 %) and hemicellulose (13.1 %). NaOH concentration exhibited significant effect on delignification during pretreatment. The highest delignification (80.42 %) was obtained by pretreatment with 2.47 % NaOH at 55.8 °C for 5.9 h removing 79.8 % lignin and 34.2 % hemicellulose from biomass, thereby increasing cell wall porosity and allowing better accessibility to saccharification enzyme. During saccharification optimization, significant effect was observed for biomass loading, enzyme concentration and temperature. Optimized saccharification condition yielded maximum saccharification (76.48 %) when hydrolysis was performed at 6.9 % biomass loading with enzyme concentration of 49.52 FPU/g substrate at 51.05 °C for 74.46 h.


Assuntos
Corchorus , Lignina , Biomassa , Lignina/química , Álcalis , Hidróxido de Sódio/farmacologia , Hidrólise
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